Pneumatic vehicle tires for commercial vehicles in which the belt is formed by four belt plies arranged one on top of the other in the radial direction, of which two belt plies are designed as working plies, the reinforcements of which are each aligned so as to enclose an angle of 15° to 24° with the circumferential direction of the vehicle tire, are known. In this case, the reinforcements of one working ply have an opposite axial direction of inclination to the reinforcements of the other working ply. The two working plies thereby form a cross-braced structure. Normally, the belt furthermore has a belt ply designed as a blocking ply underneath the working plies, the path of the reinforcements of this belt ply being such as to enclose an angle of 45° to 70° with the circumferential direction. In addition, there is typically an additional protective ply formed radially above the two working plies as a fourth ply, the path of the reinforcements of said protective ply being such as to enclose an angle of 15° to 24° with the circumferential direction. The reinforcements of these belt plies are steel cords.
Pneumatic vehicle tires of this kind are normally produced in such a way that the belt plies are formed by parallel steel cords embedded in rubber, wherein the belt plies are built up on a building drum in order to produce the tire blank. The belt, with the tread added, is joined to the toroidal carcass. Once the complete tire blank is finished, the tire blank undergoes final shaping and vulcanizing in a vulcanizing press.
It is desirable that working plies with substantially inelastic reinforcements should be formed in the pneumatic vehicle tire. This provides a high circumferential stiffness to the belt, and this has a positive effect on the abrasion of the tire and on durability. To produce pneumatic vehicle tires of this kind, the working plies are laid on the building drum with substantially inelastic steel cords embedded in rubber. However, the lack of elasticity in the steel cords then counteracts the residual elevation of the tire in the vulcanizing press, which is important for final shaping. In the pneumatic vehicle tire produced, unwanted residual stresses resulting from the residual elevation may remain in the steel cord, between the steel cord and the rubber material and in the rubber material along the steel cord. In order to avoid disadvantages—such as the overloading of the rubber material—resulting from this or to compensate them in some other way, additional effort is required. When the pneumatic vehicle tires are designed in this way, therefore, the production of the pneumatic vehicle tires is made more difficult. Additional effort is required for final shaping or for compensation of residual stresses or an unwanted restriction of the design of the belt plies in respect of the use of inelastic steel cords. However, this reduces the achievable circumferential stiffness of the belt and limits the possibility of optimizing the abrasion of the tire.